The present invention is related to providing an induction heating cooker, and particularly to providing a 4-burner electronics induction heating cook system for controlling the output according to the control input signal for operating the cooker.
The control circuit of a conventional electronics induction heating cooker includes two types of controlling the calorie amount of the cooker, for example, a timing on-off control manner and a frequency control manner.
The typical example of the timing on-off control manner is disclosed in U.S. Pat. No. 4453068 issued to Mr. Raymond M. Tucker, et al. entitled "Induction Cook-top System and Control."
An induction heating system 40 is provided, which includes a plurality of induction heating coils 118. Touch control pads are provided together with circuitry 80 for generating energizing control signals. Circuitry 80 is provided for electrically energizing the induction heating coils 118. An electronic digital processor 82 is responsive to the energizing control signals for generating energizing signals for actuating and controlling the energizing circuitry 112, 116 to thereby vary the energizing of the plurality of induction heating coils.
Similarly, the circuit is provided with a timer used as a temperature controller, a zero crossing detector, a differential amplifier, a ramp generator and an output generator. The differential amplifier includes temperature setting means and the temperature sensing means (for example thermistor) to execute the on-off switching operation of the load. The ramp generator is provided with a delaying circuit having a predetermined time so that it receives the signals having a duration of timing corresponding to the on-off switching operation of the differential amplifier to adjust the timing. The output amplifier is provided with a triac, the triggering of which corresponds to the zero crossing of the A.C. voltage source to repeatedly generate a saw-shaped wave and to induce the operation of the load, for example, a heating device, etc.
Thus, the output having the on-off time predetermined by the ramp generator controls the load by the synchronized on-off switching means and the triac of the zero voltage switch, which is connected to the differential amplifier and selected according to the temperature control requirement. Hence, it is known that the heating cooker presets the maximum heating output and controls the on-off timing of the output.
If the conventional cooker includes more than one high frequency heating device, a surge current applied by adjacent heating burners can overload a burner when operated over 1000W of the maximum heating output. The induction cook-top system disclosed in U.S. Pat. No. 4,453,068 varies the energizing of the plurality of induction coils, but was not shown relative control of the maximum output, and thus, suffers from surge currents as described above.
Also, conventional frequency control manners include a temperature frequency converter to generate the frequency converting output in response to the temperature change and change the output voltage relative to the load.
Multi-burner cookers experience inter-burner interference because adjacent burners are allowed to operate at different frequencies, and thus, interfere with each other or even influence adjacent electrical appliance to generate interference noise.